Universal balancing machine with electromagnetic hold

ABSTRACT

A WORKPIECE CARRIER IS SUPPORTED FOR TILTING TRAVEL UPON AN ARCUATELY SPHERICAL, UNIVERSAL PIVOT, WHICH PIVOT RESTS UPON A SEAT HAVING A CORRESPONDING SPHERICITY. SAID SEAT IS FORMED IN A CASTING MOUNTED UPON THE TOP SURFACE OF A HOUSING, SAID PIVOT CARRIES, AS PART OF A UNIT, THE WORKPIECE CARRIER, A ROD ELONGATED DOWNWARDLY THROUGH AND BENEATH SAID SURFACE TO RECIPROCABLY SWING WITH SAID CARRIER IN A SIMPLE HARMONIC MOTION THROUGH A PATH OF TRAVEL RSPONSIVE TO, AND DETERMINED BY, THE IMBALANCE OF A WORKPIECE ON THE CARRIR. AN ANNULAR MEMBER HAVING AN ANNULAR, SPHERICALLY CONCAVE SURFACE IS CARRIED CONCENTRICALLY ON THE LOER END OF SAID ROD TO COMPLETE SAID UNIT. AN ELECTROMAGNETIC DEVICE IS DISPOSED BENEATH SAID SURFACE TO AUTOMATICALLY AND REPEATEDLY RELEASE AND ENGAGE SAID MEMBER TO INTERRUPT SAID TRAVEL AND REDUCE, WITH EACH ENGAGEMENT, THE MOMENTUM IMPARTED TO THE UNIT, TO QUICKLY ALLOW SAID UNIT TO ATTAIN A TILTED ATTITUDE IN WHICH THE RADIAL DIRECTION AND AMOUNT OF IMBALANCE CAN BE DETERMINED, AS BY A MEASURING DEVICE CARRIED UPON THE PIVOT.

March 16, 1971 p LANNEN 3,570,278

UNIVERSAL BALANCING MACHINE WITH ELECTROMAGNETIC HOLD Filed Aug. 5, 1969 3 Sheets-Sheet l 2| e 22 20 G i-.2. "1 7L: A- '1 t We b L I llu a T I I0 :5 I 37 M5 III] III DIVST INVENTOR JOSEPH R LANNEN ATTORNEY March 16, 1971 J. P. LANNEN 3,570,278

UNIVERSAL BALANCING MACHINE WITH ELECTROMAGNETIC HOLD Filed Aug. 5, 1969 3 Sheets-Sheet 2 i T F' Jill/ 36 as 24 37a 34 F" 30 L I F I G. '7 35 g L 27 I 2, l 42 l z i an 38 28 l 4| Tl I 40 lNVENTOR JOSEPH P LANNEN ATTORNEY March 16, 1971 y LANNEN 3,570,278

UNIVERSAL BALANCING MACHINE WITH ELECTROMAGNETIC HOLD Filed Aug. 5, 1969 3 Sheets-Sheet 5 SWI swz 2 J. 447

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INVENTOR JOSEPH P. LANNEN ATTORNEY United States Patent 3,570,278 UNIVERSAL BALANCING MACHINE WITH ELECTROMAGNETIC HOLD Joseph P. Lannen, 51300 Pontiac Trail, Wixom, Mich. 48096 Filed Aug. 5, 1969, Ser. No. 852,965 Int. Cl. G01m 1/12 US. Cl. 73-483 Claims ABSTRACT OF THE DISCLOSURE A workpiece carrier is supported for tilting travel upon an arcuately spherical, universal pivot, which pivot rests upon a seat having a corresponding sphericity. Said seat is formed in a casting mounted upon the top surface of a housing, said pivot carries, as part of a unit, the workpiece carrier, a rod elongated downwardly through and beneath said surface to reciprocably swing with said carrier in a simple harmonic motion through a path of travel responsive to, and determined by, the imbalance of a workpiece on the carrier. An annular member having an annular, spherically concave surface is carried concentrically on the lower end of said rod to complete said unit. An elec tromagnetic device is disposed beneath said surface to automatically and repeatedly release and engage said memberto interrupt said travel and reduce, with each engagement, the momentum imparted to the unit, to quickly allow said unit to attain a tilted attitude in which the radial direction and amount of imbalance can be determined, as by a measuring device carried upon the pivot.

RELATED PATENTS The pivotal means of the ensuing disclosure is closely analogous to the disclosure of Pat. No. 3,181,371, issued to the present applicant on May 4, 1965, on a universal balance testing machine, showing means to lubricate such pivot under pressure. It is thought unnecessary to repeat herein the disclosure of said patent as to a pump, relief valve, and oil reservoir incorporated in the lubrication system.

BRIEF SUMMARY OF INVENTION This invention relates to universal balancing machines as above described which employ a simple harmonic motion to determine imbalance, and particularly to such machines as employ quick-acting, electromagnetic devices to repeatedly interrupt said motion, to quickly bring said unit, and a workpiece, to a stop in a tilted attitude for determination of the desired data as to imbalance of the workpiece.

In a balancing device as above described, the pivot affords reciprocable, swinging, pendulum-like travel along a path, and with a momentum, determined by the amount and radial direction of the imbalance in any workpiece placed on the carrier. Said pivot is so well lubricated that the extent of each swing carries the unit through and beyond the attitude at which the unit would eventually come to rest, in which attitude the desired data as to a workpiece may be obtained. Further, said lubrication is so eftlcient that reciprocable, swinging travel may continue for a period of time measurable in minutes before terminating in said attitude. It is desirable to reduce this period of time to be measurable in seconds.

The following specification discloses an electromagnetic device which acts quickly and repeatedly to interrupt said travel to reduce said momentum to quickly bring the unit to a stop in the attitude affording determination of the desired data.

An object of the invention is to provide in a unit, a workpiece carrier, a pivot, a rod, and said annular memice ber, as aforesaid, and to further provide a wall encircling said member, and to provide means to move said wall, at predetermined intervals, from a first position in which said travel is afforded, to a second position in which said wall releasably engages said member to interrupt said travel.

Another object is to adapt said wall to travel with said unit, and to restrain said wall and said unit from said travel when the electro-magnet is energized.

A further object is to provide means to predetermine the time of said intervals and to predetermine the number of said intervals.

These and various other objects are attained in the construction hereinafter described, and illustrated in the accompanying drawings, wherein:

FIG. 1 is a plan view of the device, showing a bubble level mounted upon the pivot means.

FIG. 2 is a vertical, partial, sectional elevational view taken on line 22 of FIG. 1, but showing the bubble level in section.

FIG. 3 is a plan view of the casting, with the pivot and level removed to show the spherical seat in which said pivot has said travel; said rod, and a sleeve encircling said rod (and hereinafter identified) are shown in section.

FIG. 4 is a vertical, partial, sectional elevational view on line 4-4 of FIG. 3, with said pivot and associated elements shown in dash line, and said sleeve partially shown in section.

FIG. 5 is a horizontal, sectional view on line 55 of FIG. 6, showing said electromagnetic device.

FIG. 6 is a partial, vertical, sectional view on line 66 of FIG. 5, showing said wall in said first position.

FIG. 7 is a view similar to FIG. 6, but on a larger scale, and showing said wall in said second position.

FIG. 8 is a diagram of the electrical circuitry by which the electro-magnet is made operable.

In these views, the reference character 1 designates a hollow base including a cover plate 2 having a central aperture 3. A casting 4 surmounts the plate 2 in a covering relation to said aperture and is rigidly bolted to the plate as indicated at 5. Integral with an upstanding on said casting is an annular seating member 6 having its upper end face spherically and concavely curved about a pivot locus 7 in the upwardly extended vertical axis of said seating member. Normally seated on and above the member 6 is an annular work carrier 8 having an enlarged lower portion 9 presenting to said seating member a spherically and convexly curved annular face complementary to that of said member. The described arrangement is such that a workpiece (not shown) loaded on the carrier 8 may tilt in unison with the carrier about the locus 7 in any direction responsive to imbalance of the workpiece.

To minimize friction between the spherical faces and thus increase sensitivity of the machine, it is preferred to subject the carrier 8 to upward pressure of a fluid, preferably oil. As best shown in FIGS. 2, 3, and 4 the member 6 is formed with a suitable number of vertical passages 10 delivering oil upwardly from an annular passage 11 at the base of said member to the spherical top face of said member through an upper annular channel 11a. The passage 11 receives oil from a tube 12 leading from a pump (not shown). Adjoining the member 6, the casting 4 is formed with inner and outer annular, open topped chambers 13 and 14 receiving oil discharging from the spherical pivot-forming faces. Said chambers are interconnected by one or more passages 15 and a tube 16 drains oil from said chambers.

A cover 9a is received upon the carrier, and is formed with a downwardly extending flange 9b having an interiorly tapered edge to minimize the possibility that oil might escape, but designed to allow travel of the carrier about the locus of said pivot.

To indicate the amount and radial direction of imbalance determined by the direction and final extent of travel of the carrier, any suitable type of device may be employed. The illustrated level 17 is seated on the outer end portion of an arm 17a radially projecting from the carrier. Screws 18 secure the inner end of said arm to the carrier. An adapter 19 to receive a workpiece (not shown) surmounts the carrier 8 and may be secured thereto by any conventional means.

A circular recess 20 is formed in the top face of the carrier 8, to receive a spacer 21. A screw 22 extends through the spacer to threadedly engage in the upper end portion 23 of a rod 24. Said upper end portion 23 is concentrically received in the carrier and retained therein by said screw. A sleeve 25 forms the inner Wall of said innermost annular chamber 13, and extends through the bottom wall of said chamber, through the annular passage 11, and the bottom wall thereof. Obviously, the sleeve must have an oil sealing engagement in said bottom walls for maximum efficiency of the lubrication system.

An annular member 26 is secured to the lower end of said rod 25, whereby the carrier 8, the rod 23, 24, and said annular shoulder form a unit to travel about the locus 7 of the radially spherical pivot of the carrier responsive to imbalance of a workpiece. Said annular member is formed with an annular, spherically concave surface 27. A screw 28 secures said member 26 in position. The lower end portion of the rod 24, also carries a disc 29 and is received in a boss 30 on said disc.

A second disc 31 is carried by the first said disc, as hereinafter explained, and is formed with a downwardly projecting annular wall 32. Studs 33 have their lower end portions threaded into the disc 31. Said studs also carry washers or the like 34. Springs 35 react between the first disc and said washers, and tend to draw the lower disc 31 into concentric engagement with the upper disc 29. Nuts 36 resist escape of the washers from the studs. It is neces sary, of course, that the disc 29 be apertured appropriately to receive the studs.

A platform 37 mounts an insulated receptacle 38. Elongated bolts 37a, received in spaced sleeves 37b, have their upper end portions threadedly received in the casting 4 as at 37c. Said receptacle is formed with a flange 39 which flares into bosses 40 to receive fastening screws 41. The receptacle 38 is recessed to receive an annular electro magnet 42 to draw the lower disc downwardly against the tension of said springs 35 and releasably hold it to interrupt the travel of said pivot and restrain the pivot, rod, disc and annular member from movement. A series of switches is caused successively to make and break circuits at predetermined intervals to afford said travel and to repeatedly restrain said elements, until the unit 8, 19, 24, 26 stops in the desired attitude in which the necessary data can be obtained.

Referring now in detail to the electrical diagram as shown in FIG. 8, it will be seen that lines 43, 44 and 45 controlled by gang switch SW1 carry electrical current to a pump motor PM which operates a pump to pump oil to lubricate the pivot. Switches SW2, SW3, and SW4 are normally open, and are closed as hereinafter described to energize said motor.

The balance of the circuitry is energized by a transformer 46 through line 48. Said circuitry is controlled by a normally closed stopping switch SW5 and a normally open starting switch SW6, and the relay R1. Upon momentary closing of the starting switch SW6, the relay R1 is energized and influences switch SW7 to make contact and close a circuit through line 49, SW7, line 50, relay R1, and line 51 to relay R2.

The contacts of switch SW7 are held closed by the energization of relay R1 until the normally closed switch SW5 is depressed to interrupt the circuit. Energization of relay R2 closes switches SW2, SW3, and SW4 to the aforesaid motor, and said circuitry is also maintained until energization of relay R2 is interrupted by the use of switch SW5. A line 52 connects with line 48 to complete the circuitry above described. From line 50, a circuit is established through line 53 and its continuation 53w and through switches SW10, electromagnet 42, and switch SW11 to line 48. Energization of the electromagnet 42 causes said electromagnet to engage the disc 31 and hold the unit comprised of carrier 8, workpiece adapter 19, and the rod 24 from pivotal travel while a workpiece is in a tilted attitude.

The normally open starting switch SW8 in line 54 is momentarily depressed, to energize the timer motor TM. Said timer motor causes the concurrent rotation of a bank of concentric rotary cams about a mutual axis. Such cams are of a conventional nature well known in the art, and are not displayed in the drawings. Once the timer motor is energized, a cam in said bank of cams mechanically closes the normally open switch SW9 and maintains said switch in a closed position until a complete revolution of the bank of cams has been elfected.

At this point the electromagnet 42 is still energized, and restraining the balancing unit from pivotal travel. As said bank of cams rotates, a cam briefly closes the contacts of switch SW12 affording the flow of current through line 55 and 59 to relay R3 and relay R4, energizing said relays to open normally closed switch SW10 and switch SW11, which, when open, isolates the electromagnet in the circuit, causing it to be de-energized and affording pivotal travel of the carrier and the rod 24 and the disc assembly 29, 31. Switch SW12 is held closed very briefly, and allowed to reopen, de-energizing relays R3 and R4 and allowing switch SW10 and switch SW11 to close and re-energize electromagnets 42 causing the disc 31 to be drawn into contact with the electromagnet to restrain the carrier unit from further pivotal travel. In sequence, switch SW13 is closed briefly to afford a circuit through line 56 to energize relay R3 and R4, and is allowed to open to repeat the brief period of pivotal travel and the interruption thereof. Switch SW14, through line 57, switch SW15 through line 58, and switch SW16 through line 59, sequentially repeat the predetermined timing of the pivotal travel and the interruption thereof as said switches are successively closed and allowed to open by respective cams. Any desired number of interruptions of travel can be obtained by addition of further switches and circuitry.

In setting up the above described device, a master workpiece, previously balanced, is placed upon the workpiece carrier. The bubble in the level is centered with the vertical axis of the level parallel with the vertical axis of the pivot. The aforesaid unit is freed of the electromagnetic control, and the workpiece and unit are allowed to oscillate. With a stop watch, the number of full cycles of oscillation per minute are timed, and the resultant figure is divided by 60 to determine the number of cycles per second. This figure is then divided by four to obtain the time required for one-quarter of a full oscillation, that is from the maximum extent of travel to the mid-point of such travel. The rotary cams are then adjusted to actuate the switches to stop the travel of the unit within consecutive one-quarter cycles of oscillatory travel.

What I claim is:

1. In a machine for-testing imbalance of an annular workpiece, said machine including a fixed element, a workpiece carrier, and annular means to afford universal pivotal travel of said carrier to a tilted position to measure imbalance of a workpiece, and means to measure such imbalance,

a rod carried by and extending downwardly from said annular means and tiltable therewith,

an annular member carried by said rod,

an annular wall encircling said annular member,

support means supporting said wall on said rod to afford approximately vertical travel of said Wall between a first position in which said carrier is afforded pivotal travel to a tilted attitude responsive to imbalance of a workpiece on said carrier, and a second position in which said annular wall engages said fixed element and said carrier is releasably, rigidly restrained in a tilted attitude,

such restraint being transmitted to the carrier through said rod by engagement of the wall with said annular member,

means for moving the annular wall between said first and second positions.

2. In a machine as set forth in claim 1,

said annular member being formed with an annular,

spherically concave face,

the interior face of said wall imposing restraint on said concave face in said second position of said annular wall.

3. In a machine as set forth in claim 1,

mounting means to mount said annular wall on said rod for pivotal travel with said rod and said carrier, said mounting means including one or more elements yieldably urging said annular wall to said first position, to afford the pivotal travel of the carrier to a tilted attitude,

said means for moving the annular wall including means to abruptly move said annular wall to said second position to releasably restrain said carrier in said tilted attitude.

4. In a machine as set forth in claim 3,

said annular wall being formed with a transversely extending annular flange,

a corresponding annular disc carried by said rod,

said mounting means including one or more rods slidably passing through said disc and having the lower end portion of each rod secured to said flange,

a protuberance carried by the upper end portion of each said rod,

said one or more elements being spring means reacting between said disc and said protuberance to urge said annular wall to said first position.

5. In a machine as set forth in claim 4,

said means to move said annular wall to said second position being electromagnetic,

whereby said annular Wall and annular flange may be drawn approximately vertically downwardly from the first position to the second position when said carrier is tilted in an appropriate attitude to measure imbalance.

References Cited UNITED STATES PATENTS 3,455,170 7/1969 Lannen 73-483 25 JAMES J. GILL, Primary Examiner 

